The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
* 0-21 * * *
This cron command translates to the following (in Human-Readable format):
“Every minute between 12:00 am and 9:00 pm.”
What is a Cron Job & Crontab?
A cron job is a task that is scheduled to run at a specific time or interval. Cron jobs are typically used for automating system maintenance or administration tasks, such as running backups or sending email reports.
A crontab is a table or list of commands that are scheduled to run at specified times. The commands in a crontab file (also called a “cron table”) are normally executed by the cron daemon, which runs in the background and executes these commands automatically.
Every cron job uses five fields. Here is an explanation of what each field does in this cron, which runs “every minute between 12:00 am and 9:00 pm“:
FUN FACT: When editing your crontab, it is important to use a text editor that supports Unix-style line endings (LF), as opposed to Windows-style line endings (CRLF)..
You might want to set up a crontab or cron job to run every minute between 12:00 am and 9:00 pm for several reasons, including:
- Sending a daily update email to all users of a service
- Checking for new user registrations and sending a welcome email
- Calculating daily statistics and saving them to a database
- Generating a report of yesterday’s sales and sending it to the sales team
Similar Cron Jobs
You might also want to run a crontab:
- every 20 minutes
- every 9 minutes
- every 26 minutes
- every 4 minutes
- every minute between 7:00 am and 12:00 pm
- every minute between 5:00 am and 7:00 am
FUN FACT: Cron is typically used for things like system maintenance tasks, running backups etc..
In this article, you learned how to set up a cron job that runs every minute between 12:00 am and 9:00 pm. Please share this page with friends and colleagues if you find it useful.
If you have any questions, please don’t hesitate to comment below.
If you are looking for cron jobs that run at certain minutes, hours, days, weekdays, or months, or if you are looking for miscellaneous cron jobs, then check out our relevant sections, or visit our crontab cheat sheet for a list of hundreds of popular cron jobs.